This study will explore the efficacies of several practical short-term (peri-procedural) intravenous fluid regimens in the prevention of post- endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis (PEP). PEP is the most common serious ERCP-related adverse event (AE), occurring in 5-15% of patients, and associated with significant morbidity, mortality, and healthcare utilization. Given the current lack of data on effectiveness of short-term fluid regimens in PEP prevention to inform practice, the results of the proposed study have the strong potential to impact ERCP practices worldwide, whether positive or negative.

Inclusion Criteria:

1. age 18-75 years (due to higher likelihood of undiagnosed cardiac disease or renal insufficiency in patients >75 years of age)
2. ability to give informed consent
3. native major papillary anatomy
4. ability and willingness to obtain bloodwork the day after ERCP

Exclusion Criteria:

1. prior ERCP with sphincterotomy and/or sphincteroplasty
2. confirmed or suspected cholangitis or sepsis
3. confirmed pancreatitis, hyperlipasemia, or hyperamylasemia within the preceding 7 days
4. NYHA Class II or greater heart failure
5. active pulmonary edema
6. myocardial infarction or ischemia within the preceding 3 months
7. renal insufficiency with CrCl < 40 mL/minute
8. CPT Class B or C cirrhosis and/or end-stage liver disease
9. room air oxygen saturation <90% or requirement of home O2
10. hypernatremia with Na+ ≥ 150 mEq/L or Na+ <130 mEq/L
11. uncontrolled hypertension or hypotension
12. pregnant status